A Great Piece of Online Marketing

I saw a really great piece of online marketing the other day that instantly made me want to click it:

It's a great piece of reverse psychology - “don't buy my book”! Then the author directs you to a free download.

It works because firstly you can see it's a credible, published book that you can even start to read on Amazon and secondly because it really feels like the author is giving you inside access to his book because you’re a trusted friend.